The present invention relates generally to telecommunications services. More particularly, the present application relates to a method and system for providing enhanced caller identification information including screening invalid calling party numbers.
Telecommunications service providers typically offer services that attempt to provide customers with information that enables them to determine whether or not to accept a call before answering the call. One service that provides such information is caller identification (“Caller ID”). Standard Caller ID services generally provide a customer with an indication of who is calling without requiring the customer to answer the call. These systems typically retrieve information about the calling party from a database and provide that information to the called party. Customer premise equipment (CPE) in the form of a display device is generally used to provide the called party with a visual readout of the name and/or telephone number associated with the calling party.
However, the effectiveness of Caller ID systems can be reduced due to a number of different occurrences. One such occurrence is the inability of a service provider to provide the standard Caller ID information for a particular incoming call. A service provider may not be able to provide the standard Caller ID information if the Caller ID information is blocked by the calling party, or if the Caller ID information is unavailable or incomplete. This may occur, for example, if the calling party pressed *67 when initiating the call.
When the standard Caller ID information cannot be provided, the called party is not adequately informed about who is calling and cannot determine whether or not to accept the incoming call before answering the call. Because the effectiveness of Caller ID systems is greatly reduced when information cannot be provided, an improved system and method for providing caller identification information that overcome these deficiencies are needed.
Patent application Ser. No. 09/122,484, filed Jul. 24, 1998 and commonly assigned to the assignee of the present application, is incorporated herein by reference. This patent application discloses a method and system for providing a called party with audible caller identification information when standard caller identification cannot be provided. When standard caller identification cannot be provided, the call is blocked and a request for audible caller identification is transmitted to the calling party. The audible information is subsequently transmitted to the called party.
Patent application Ser. No. 09/253,339, filed Feb. 19, 1999, is also incorporated herein by reference. This application discloses a method for providing enhanced caller identification information when per line blocking of Caller ID is present. When per line blocking is activated for a subscriber line, the Caller ID information for that line is never transmitted by the system.
In the systems disclosed in the incorporated patent applications, subscribers that interface with network equipment via Primary Rate Interface Trunk Groups have the ability to illegally manipulate the ten digit directory number that is placed in the Calling Party ID field of the set up message that is communicated by the network. Instead of the true calling party information, such subscribers can place, for example, all zeroes, all ones, numbers having fewer than ten digits, ten digit numbers that begin with a 0 or 1. Alternatively, such callers can place an invalid Numbering Plan Area (NPA) or area code number, plus seven digits, in the Calling Party ID field.
In any of these cases, and by not blocking the entry by setting the entry to presentation allowed, the call will bypass the system of the incorporated patent applications and will be presented to the called party. Subscribers to the service will see displayed on their Caller ID equipment the phony directory number and an unknown name. This shields the identity of the calling party from the service subscriber.
Accordingly, there is a need for a system and method which permit detection and screening of invalid calling party numbers before the call is communicated to the called party.